System for controlling mower drive wheels

ABSTRACT

A zero-turn-radius mower includes a chassis, a pair of drive wheels for supporting the chassis above a ground surface, an engine, and a pair of transmissions or other drive mechanism for driving the drive wheels. A manually-moveable brake lever enables an operator to selectively brake the drive wheels and a manually-moveable bypass lever enables the operator to selectively engage bypass functions of the transmissions. The brake lever and the bypass lever are mechanically coupled such that engaging the brake lever causes the bypass lever to be engaged with the brake lever, but engaging the bypass lever does not cause the brake lever to be engaged. The brake lever and the bypass lever each including a locking mechanism that retains the respective lever in an engaged position.

FIELD

Embodiments of the present invention relate to systems for controllingoperation of the drive wheels of zero-turn-radius mowers.

BACKGROUND

A zero-turn-radius or “zero-turn” vehicle is a vehicle with a turnradius that is effectively zero inches. Zero-turn riding lawnmowers canreduce the amount of time required to mow yards and other areas becausethey can cut closely around trees, fences and other obstacles andtherefore reduce or even eliminate the need for trimming. Anotheradvantage of these mowers is that they pivot through 180 degrees withoutleaving a circle of uncut grass.

Different makes and models of zero-turn riding lawnmowers achieve azero-turn radius in different ways, but hydraulic speed control of thedrive wheels is the most common method. A typical zero-turn mower haseach of its drive wheels connected to a separate hydrostatictransmission. A hydrostatic transmission is a continuously variabletransmission that creates wheel rotation using pressurized fluid.Rotational force from an engine drives a pump that pressurizestransmission fluid. A steering/speed lever, joystick or other usercontrol device may be moved to control the flow of fluid through eachtransmission and thus control the rotational speed or theforward/reverse direction of each drive wheel. If one drive wheel turnsmore rapidly than the other, the mower moves along a curved path. Ifboth wheels turn at the same speed, the mower follows a straight path.If one wheel stops and the other turns, or if the wheels turn inopposite directions, the mower pivots or rotates.

The above section provides background information related to the presentdisclosure which is not necessarily prior art.

SUMMARY

A mower constructed in accordance with an embodiment of the presentinvention comprises a chassis, a pair of drive wheels for supporting thechassis above a ground surface, and an engine and a drive mechanism fordriving the drive wheels. A manually-moveable brake lever selectivelybrakes the drive wheels, and a manually-moveable bypass leverselectively bypasses the drive mechanism. The brake lever and the bypasslever are mechanically coupled such that engaging the brake lever causesthe bypass lever to be engaged with the brake lever.

A mower constructed in accordance with another embodiment of the presentinvention comprises a chassis, a pair of drive wheels for supporting thechassis above a ground surface, a seat supported on the chassis, and anengine and a pair of transmissions for driving the drive wheels.

A pair of manually-moveable control handles enable control of thetransmissions, wherein the control handles are positioned proximate theseat such that an operator seated in the seat can operate the controlhandles. A manually-moveable brake lever selectively brakes the drivewheels, and a manually-moveable bypass lever selectively engages bypassfunctions of the transmissions. The brake lever and the bypass lever aremechanically coupled such that engaging the brake lever forces thebypass lever to be engaged with the brake lever, but engaging the bypasslever does not force the brake lever to be engaged. Furthermore, thebrake lever and the bypass lever are positioned proximate the seat suchthat an operator seated in the seat can operate the brake lever and thetransmission bypass lever.

This summary is provided to introduce a selection of concepts in asimplified form that are further described in the detailed descriptionbelow. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter. Other aspectsand advantages of the present invention will be apparent from thefollowing detailed description of the embodiments and the accompanyingdrawing figures.

DRAWINGS

Embodiments of the present invention are described in detail below withreference to the attached drawing figures, wherein:

FIG. 1 is a front isometric view of a zero-turn-radius mower including abraking and bypass control assembly constructed in accordance withembodiments of the present invention.

FIG. 2 is a front isometric view of certain components of the mower ofFIG. 1 including a pair of transmissions and the braking and bypasscontrol assembly.

FIG. 3 is a front isometric view of the transmissions and the brakingand bypass control assembly of FIG. 2 including a push-pull cable systemoperably coupling levers of the control assembly with braking and bypasslevers on the transmissions.

FIG. 4 is a rear isometric view of a brake lever and bypass lever of thebraking and bypass assembly, illustrating both levers in an unengagedposition.

FIG. 5 is a rear isometric fragmentary view of the brake lever andbypass lever illustrating both levers in an unengaged position.

FIG. 6 is a front isometric view of the brake lever and the bypass leverillustrating the bypass lever in an engaged position and the brake leverin an unengaged position.

FIG. 7 is a rear isometric view of the brake lever and the bypass leverillustrating the bypass lever in an engaged position and the brake leverin an unengaged position.

FIG. 8 is a front isometric view of the brake lever and the bypass leverillustrating both levers in an engaged position.

FIG. 9 is a rear isometric view of the brake lever and the bypass leverillustrating both levers in an engaged position.

The drawing figures do not limit the present invention to the specificembodiments disclosed and described herein. The drawings are notnecessarily to scale, emphasis instead being placed upon clearlyillustrating the principles of the invention.

DETAILED DESCRIPTION

The following detailed description of embodiments of the inventionreferences the accompanying drawings. The embodiments are intended todescribe aspects of the invention in sufficient detail to enable thoseskilled in the art to practice the invention. Other embodiments can beutilized and changes can be made without departing from the scope of theclaims. The following detailed description is, therefore, not to betaken in a limiting sense. The scope of the present invention is definedonly by the appended claims, along with the full scope of equivalents towhich such claims are entitled.

In this description, references to “one embodiment”, “an embodiment”, or“embodiments” mean that the feature or features being referred to areincluded in at least one embodiment of the technology. Separatereferences to “one embodiment”, “an embodiment”, or “embodiments” inthis description do not necessarily refer to the same embodiment and arealso not mutually exclusive unless so stated and/or except as will bereadily apparent to those skilled in the art from the description. Forexample, a feature, structure, act, etc. described in one embodiment mayalso be included in other embodiments, but is not necessarily included.Thus, the present technology can include a variety of combinationsand/or integrations of the embodiments described herein.

A lawnmower 10 constructed in accordance with various embodiments of theinvention is illustrated in the drawing figures. The lawnmower 10 may bea zero-turn-radius type lawnmower or any other type of mower with asmall turning radius.

Initially referring to FIGS. 1-3, an embodiment of the mower 10 broadlycomprises a chassis 12; a seat 14 supported on the chassis forpermitting an operator to sit or stand on the mower; a mower deck 16with one or more cutting blades notably attached to or supported underthe chassis; a pair of drive wheels 18, 20 and a pair of caster wheels22, 24 for supporting the chassis and mower deck above a ground surface;an engine 26; a pair of transmissions 28, 30 coupled between the engineand the drive wheels for driving the drive wheels; and a pair ofmanually-moveable drive control handles 32, 34 for controlling theforward and reverse drive functions of the transmissions; and a brakingand bypass control assembly 36 including a manually-moveable brake lever38 for braking the drive wheels and a manually-moveable bypass lever 40for engaging a bypass function of the transmissions 28, 30.

The chassis 12, seat 14, mower deck 16, drive wheels 18, 20, casterwheels 22, 24, engine 26, and transmissions 28, 30 are conventional andare thus not described in detail herein. Embodiments of the lawnmower 10may also comprise conventional fuel tanks panels, electrical controlsystems, steering assemblies, batteries, and other components that willalso not be described in detail herein. The drive control handles 32, 34and related components were described in an earlier-filed patentapplication titled “ZERO-TURN LAWNMOWER WITH IMPROVED CONTROL HANDLES,”filed on Nov. 8, 2012 and assigned application Ser. No. 13/569,602. Theearlier-filed patent application is incorporated by reference herein inits entirety.

The braking and bypass control assembly 36 may be installed on any sizeand type of lawnmower. Thus, the present invention is not limited to theparticular mower 10 described and illustrated herein. By way of example,the drive wheels of some mowers may be positioned at the front of themower or positioned intermediate front and rear caster wheels. Theposition of the drive wheels is not important to the present invention,which may be implemented in mowers with various different wheelconfigurations. Furthermore, while the mower 10 includes twotransmissions 28, 30, each associated with one of the drive wheels 18,20, it will be appreciated that the present invention is not so limitedand may be used with other types of drive mechanisms. By way of example,the present invention may be used with a mower that includes a singletransmission configured to drive both wheels 18, 20, a single hydraulicmotor configured to drive both wheels 18, 20, or two hydraulic motorseach associated with one of the wheels 18, 20.

The transmissions 28, 30 include levers or other control elements foractuating braking and bypass functions of the transmissions, asdiscussed below in greater detail. By way of example, the transmissionsmay be the ZT-2800 model transaxle sold by HYDRO-GEAR®. As used herein,“bypassing” a transmission means allowing the drive wheel associatedwith the transmission to spin freely without being driven or impeded bythe transmission. Thus, bypassing a transmission may involve completelydisengaging the associated drive wheel from the transmission ordisabling the transmission so that it simply follows movement of theassociated drive wheel. In certain embodiments of the inventiondescribed and illustrated herein, bypassing the transmissions 28, 30involves actuating levers on the transmissions 28, 30 that engage anddisengage a bypass function built into the transmissions. The presentinvention is not so limited, however, and other methods of bypassing atransmission are within the ambit of the invention, includingdisengaging a drive belt.

With particular reference to FIGS. 4-9, the brake and transmissionbypass control assembly 36 is illustrated. The assembly 36 includes amanually-moveable brake lever 38 for selectively braking the drivewheels 18, 20, a manually-moveable bypass lever 40 for selectivelyengaging the bypass functions of the transmissions 28, 30, and apush-pull cable control system 42 operably coupling the brake lever 38and the bypass lever 40 with the transmissions 28, 30 thr actuatingbraking and bypass functions of the transmissions 28, 30.

The brake lever 38 is generally L-shaped with a handle portion 44 and aleg portion 46. The lever 38 is pivotably connected to a bracket 48 thatis fixedly connected to the chassis 12 and is pivotable between anengaged position (FIGS. 8-9) and a disengaged position (FIGS. 4-7). Amanually-moveable locking mechanism 50 retains the brake lever 38 in theengaged position. More particularly, the locking mechanism 50 includes ahandle portion 52 and a lock portion 54 and is pivotably attached to thehandle portion 44 of the brake lever 38. When the brake lever 38 ismoved from the disengaged position to the engaged position, a notch 56in the lock portion 54 of the locking mechanism 50 engages a fixed lockbar 58 positioned above the brake and transmission bypass levers 38, 40to retain the brake lever 38 in the engaged position until the operatormanually moves the handle portion 54 to release the mechanism 52 fromthe bar 58.

The handle portion 44 of the brake lever 38 may be between about sixinches and eighteen inches in length, and may particularly be about teninches, about twelve inches or about fourteen inches long. The legportion 46 of the brake lever 38 may be between about one inch long andabout six inches long, and may particularly be about two inches, aboutthree inches or about four inches long. While the leg portion 46 isillustrated as being substantially normal to the handle portion 44, itwill be appreciated that the leg 46 and the handle 44 portions may beseparated by virtually any angle, including angles within the range offrom about thirty degrees to about one hundred fifty degrees.

The brake lever 38 includes a bolt 60 or similar structural elementextending laterally to engage the transmission bypass lever 40 such thatmoving the brake lever 38 from the disengaged position to the engagedposition forces the bypass lever 40 to also move from the disengagedposition (FIGS. 4-5) to the engaged position (FIGS. 6-9). With thisconfiguration, the operator may simultaneously engaged the brake lever38 and the bypass lever 40 by simply shifting the brake lever 38 to theengaged position.

The bypass lever 40 includes a handle portion 62, a leg portion 64 and alocking mechanism 66 that are similar or identical to the handle portion44, the leg portion 46 and the locking mechanism 50 of the brake lever38 described above, except that the leg portion 64 of the bypass lever40 includes a notch 68 or other structural element for engaging the bolt60 of the brake lever 38 when the brake lever 38 is moved to the engagedposition to thereby force the bypass lever 40 into the engaged positionas well.

A pair of extension springs 70, 72 attached to the locking mechanisms50, 66 and to the levers 38, 40 bias the locking mechanisms 50, 66 in alocked position so that once the locking mechanisms 50, 66 engage thelock bar 58, the operator must manually push downward on the handleportions of the locking mechanisms 50, 66 to release them from the lockbar 58.

To use the mower 10, an operator seats himself in the seat 14 and placeshis forearms on the armrests or to his sides if no armrests areprovided. Because the control handles 32, 34 are positioned outboard ofthe seat and extend upwardly and not horizontally toward the seat, theoperator can quickly and easily enter or exit the seat with nointerference from the control handles 32, 34.

The operator then starts the mower in a conventional manner and movesthe two handles 32, 34 back and forth to control the direction and speedof the mower. To brake the drive wheels 18, 20, the operator pulls thebrake lever 38 upward from the disengaged position to the engagedposition. The bypass lever 40 will follow the movement of the brakelever 38, as explained above, and both locking mechanisms 50, 66 willengage the lock boar 58 to fix the levers 38, 40 in the engagedposition, as illustrated in FIGS. 8-9. To bypass the transmissions 28,30, the operator pulls the bypass lever 40 upward from the disengagedposition to the engaged position, wherein the bypass locking mechanism66 engages the lock bar 58 and fixes the bypass lever 40 in the engagedposition while the brake lever 38 remains in the disengaged position, asillustrated in FIGS. 6-7. Thus, the brake and bypass control assembly 36allows the operator to bypass the transmissions without braking thedrive wheels so that drives wheels 18, 20 spin freely and the mower 10can be rolled.

The push-pull cable system 42 operably couples the leg portion 46 of thebrake lever 38 to a lever on each of the transmissions 28, 30 thatactuates a braking mechanism built into the transmissions 28, 30.Similarly, push-pull cable system 42 operably couples the leg portion 64of the bypass lever 40 to a lever on each of the transmissions 28, 30that actuates a bypass mechanism built into the transmissions 28, 30.

Although the invention has been described with reference to thepreferred embodiment illustrated in the attached drawing figures, it isnoted that equivalents may be employed and substitutions made hereinwithout departing from the scope of the invention as recited in theclaims. By way of example, the particular size, shape and placement ofthe brake lever and the bypass lever is not critical to the presentinvention and may vary from one embodiment to another. Furthermore,while the brake lever 38 engages a braking function of the transmissions28, 30 in the embodiment described herein, in other embodiments of theinvention the brake lever 38 may engage a brake that directly contactsthe drive wheels.

Having thus described the preferred embodiment of the invention, what isclaimed as new and desired to be protected by Letters Patent includesthe following:
 1. A mower comprising: a chassis; a pair of drive wheelsfor supporting the chassis above a ground surface; an engine and a drivemechanism for driving the drive wheels; a manually-moveable brake leverfor selectively braking the drive wheels; and a manually-moveable bypasslever for selectively bypassing the drive mechanism, the brake lever andthe bypass lever being mechanically coupled such that engaging the brakelever causes the bypass lever to be engaged with the brake lever.
 2. Themower of claim 1, the brake lever and the bypass lever being configuredsuch that engaging the bypass lever does not cause the brake lever to beengaged.
 3. The mower of claim 1, the brake lever including amanually-operated locking element for automatically locking the brakelever into an engaged position and selectively releasing the brake leverfrom the engaged position.
 4. The mower of claim 1, the bypass leverincluding a manually-operated locking element for automatically lockingthe bypass lever into an engaged position and selectively releasing thebypass lever from the engaged position.
 5. The mower of claim 1, furthercomprising a seat supported by chassis.
 6. The mower of claim 5, thebypass lever and the brake lever being positioned proximate the seatsuch that an operator can reach and operate the levers while seated inthe seat.
 7. The mower of claim 1, the brake lever being connected to abraking mechanism via a push-pull control cable.
 8. The mower of claim1, the bypass lever being connected to a bypass mechanism via apush-pull control cable.
 9. The mower of claim 1, further comprising afirst manually-moveable control handle for controlling a first drivewheel and a second manually-moveable control handle for controlling asecond drive wheel.
 10. The mower of claim 9, each of the controlhandles extending upwardly and being mounted outboard of opposite sidesof the seat so as not to block an operator's ingress or egress from theseat.
 11. The mower of claim 1, the brake lever and the bypass leverbeing mechanically coupled such that engaging the brake lever forces thebypass lever to be engaged simultaneously with the brake lever.
 12. Themower of claim 1, each of the brake lever and the bypass lever includinga handle portion and a leg portion separated by an angle of between 30and 150 degrees, the leg portion of the brake lever including a lockingelement that engages the leg portion of the bypass lever to therebycause the bypass lever to be engaged when the brake lever is engaged.13. The mower of claim 1, the brake lever and the bypass lever beingpositioned within two inches of one another and moving in parallel,co-extensive paths of motion.
 14. A mower comprising: a chassis; a pairof drive wheels for supporting the chassis above a ground surface; aseat supported on the chassis; an engine and a pair of transmissions fordriving the drive wheels; and a pair of manually-moveable controlhandles for controlling the transmissions, the control handles beingpositioned proximate the seat such that an operator seated in the seatcan operate the control handles; a manually-moveable brake lever forselectively braking the drive wheels; and a manually-moveable bypasslever for selectively engaging bypass functions of the transmissions,the brake lever and the bypass lever being mechanically coupled suchthat engaging the brake lever forces the bypass lever to be engaged withthe brake lever, but engaging the bypass lever does not force the brakelever to be engaged, the brake lever and the bypass lever beingpositioned proximate the seat such that an operator seated in the seatcan operate the brake lever and the transmission bypass lever.
 15. Themower of claim 14, the brake lever including a manually-moveable lockingmechanism for automatically locking the brake lever in an engagedposition and selectively releasing the brake lever from the engagedposition.
 16. The mower of claim 14, the bypass lever including amanually-moveable locking mechanism for automatically locking the bypasslever in an engaged position and selectively releasing the brake leverfrom the engaged position.
 17. The mower of claim 14, each of the brakelever and the bypass lever including a forwardly-extending handleportion and a downwardly-extending leg portion and being configured topivot about a point proximate an intersection of the handle portion andthe leg portion, the leg portion of the brake lever including a lockingelement that engages the leg portion of the bypass lever to therebycause the bypass lever to be engaged when the brake lever is engaged.18. The mower of claim 17, the leg portion of the brake lever beingconnected to a braking mechanism on each of the transmissions via apush-pull control cable.
 19. The mower of claim 17, the leg portion ofthe bypass lever being connected to a transmission bypass mechanism oneach of the transmissions via a push-pull control cable.
 20. The mowerof claim 14, each of the control handles extending upwardly and beingmounted outboard of opposite sides of the seat so as not to block anoperator's ingress or egress from the seat.